Method of perforating separated obstructions in hollow walls.



A. R. LOCKE. METHOD 0F PERFORATING SEPARATED OBSI'RUCTIONS IN HOLLOWWALLS.

APPLICATION FILED JAN. I5. 191.3.

Patented Sept. 21, 1915.

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APPLICATION FILED JAN.15.'1913.

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ALBERT R. LOCKE, OF CHICAGO, ILLINOIS.

METHOD OF PERFORATING SEPARATED OBSTRUCIIONS IN HOLLOW WALLS.

Application filed January 115, 1913.

To all whom t may concern Be it known that I, ALBERT R. Looxn, a citizenof the United States, residing at Chicago, in the county of Cook andState of Illinois, have invented certain new and useful Improvements inMethods of Perforating Separated bstructions in Hollow Walls, of whichthe following is a specification.

My invention relates to a method of drilling holes through a series ofcomparatively inaccessible separated bodies such as joists and othersuch supports in a hollow wall, and is especially applicable as a meansfor installing electric wires `and interior conduits for said wires, inthe spaces between the plastered sides of a vertical hollow wall andbetween the floor of one room and the ceiling of a subjacent room.

My new and improved method is especially adapted and valuable for use ininstalling wires, cables, and conduits in buildings that have beencompleted, although it may be employed with great saving and cost oflabor in buildings before the walls have been plastered or otherwisefinished.

In placing wires and conduits therefor in a hollow wall in whichperforatable supports such as wooden joists, studs and the like arecontained at intervals, such supports must necessarily be perforatedwhen lines of wires or conduits are extended at an angle to thelongitudinal dimensions of such supports. Heretofore it has beennecessary to tear up a portion of the floors or walls in finishedbuildings before such supports could be perforated for the introductionof wires and conduits.

In the practice of my invention it is not necessary to disturb the wallsfurther than to make a relatively small aperture through such wall orfloor, as at a point where an outlet box is to be located. Through thisaperture or opening a suitable drill or bit is inserted and, by thismeans of my method, a series of apertures may be drilled or boredthrough the successive joists or studs in perfect alinement to someobjective point, and at right angles to the application of power.

In carrying my method into effect I provide a suitable drill stock and arigid, composite, bit extension, the latter comprising a series ofseparable sections capable of being inserted through said opening andconveniently joined into a rigid whole until enough of said sectionshave been added to said bit Specification of Letters Patent.

of the boring apparatus.

Patented Sept. 21, 1915.

Seria No. 742,090.

desired to be made a flexible shaft may be connected to the rear end ofthe elongated bit extension, without the necessity of making furtherextensions thereto by use of additional relatively short sections.

In the drawings, Figure l is a section of a floor, showing theapplication of the drilling device as a means for carrying my inventioninto effect. Fig. 2 is a similar but somewhat smaller section, showingthe application of the flexible shaft as a means for rotating theelongated bit extension and bit. Said shaft is herein shown adapted topass through the perforations made by the bit. rIhe bit is held insubstantial alinement by the rigid extension, so that all of the holeswill be made in substantially the same horizontal plane. Fig. 3 is anenlarged section Fig. 4: is an end view of the head of said apparatus.Fig. 5 is a section of a portion of the flexible shaft.

In all the views the same reference characters are employed to indicatesimilar parts.

l1, l2, 13, and 14 are a series of separated joists for supporting thefloor l5 and ceiling 16. It is desirable to perforate these joists, inthe manner substantially as shown in Fig. l, for a distancesubstantially equal to the length of the wires or conduit to beinserted. These joists areusually 16 inches apart, from center tocenter, and run from 2 to 3 inches thick when they are composed of wood.

Before the drilling apparatus is inserted into the space between thelicor and the ceiling, it is necessary to make a hole in the' ceiling orin the fioor for the purpose of inserting the bits, sections of shaft,and the boring tool, and also for the purpose of providing room orrepose for an outlet box.

After a hole has been driven through the ceiling or wall an expansibleshield 25 is contracted and placed in the hole, expanded, and secured inexpanded position.v A flange 27 prevents its withdrawal until it hasbeen again contracted. The shield 25 protects the raw surfaces of thehole made in the ceiling or wall and prevents them from being chipped orbroken away and also prevents contact of the soiled hands of the workmanwith the wall while work is being done through the aperture provided ina manner described.

The bit stock, or means for rotating the bit, consists of the tube 29.which may be of any convenient and suitable length and has a head 30secured to the upper end thereof, as by screw threads, and a casing 31similarly secured to the lower end thereof. A hollow shaft passesthrough the tube 29 and has secured on its lower end a pinion 33 and onits upper end a bevel gear wheel 34. A gear wheel 35 is contained in thecasing 31 and in constant mesh with the pinion 33 and is adapted to berotated by any means that may be secured to the coupling member 36.

A bevel gear wheel 37 has its axis at right angles to that of the wheel34 and is in constant mesh therewith and is adapted to be turnedthereby. A screw threaded bitholding stock 38 is adapted to be movedlongitudinally through the head 30. .lt is provided with a spline 3f) inwhich a feather 40 is adapted to be freely moved. The feather 40 is alsosecured in the bevel gear wheel 37 so that when the gear wheel 37 isrotated the screw 38 is positively rotated therewith. A cylindrical nut4.1 is contained within the head 30 and has threaded engagement with thestock 38. Now, if the shaft 32 be rotated the bevel gear wheel 37 willbe rotated through the agency of the bevel gear wheel 34, and if the nut41 be 1 unrestrained the said nut 41 and the stock 38 will be rotatedtogether, but if the nut 41 be held against rotation then the stock 38will be rotated and longitudinally advanced from the head to the rightor to the left in accordance with the direction of rotation of the shaft32. For the purpose of holding the nut 41 against rotation, I provide ascrew threaded shaft 42 provided with a knurled head 43 and adapted toscrew into the casing 31. The shaft 42 is reduced, as at 43, to providea shoulder 44 for the spring 45. The reduced end 43 enters a plug 46which has direct bearing upon the cylindrical nut 41. The tension of thespring on the thrust plug 46 may be varied by turning the head 43. Ifthe shaft 42 is turned to the right more tension is applied to thespring 45 and the plug 46 is pressed more firmly against the screw nut41 to retain it against rotation and by this means the speed ofadvancement of the stock 38 may be varied by varying the slip `or therotative stability of the nut 41. It will be ,understood that if the nut41 is positively held against rotation the reciprocating movement of thestock 38 will be at its maximum speed and any slip between the plug 46and the nut 41 will reduce the speed of the stock 38 in its lateralmovement.

The boring bit 47 is connected to the stock 38 by means of a couplingcomprising a male and a female portion 48 and 49 respectively. The maleportion 48 is tapered as at 50, and is provided with an axial bore as at51, and a transverse bore as at 52. The female portion 49 is providedwith a transverse bore as at 53, and a parallel bore as at 54. rl`hetapered portion 50 of the coupling enters the transverse bore 54. Alatch bolt is contained in the bore 52 and is yieldingly held with oneend projecting from the bore 52 by means of a spring 56. A plug 57 isadapted to slide freely in the bore 51 and is held in an outwardposition by means of the spring 56 which is provided on its outer endwith a taper, as at 58. The spring-pressed latch bolt 55 is providedwith a corresponding tapered notch in which the end 58 projects. lfpressure be applied on the outer end of the latch bolt 55, the bolt 57will be pushed inwardly, by the operation of the tapering portions 58and 59 of the respective parts, against the resilient yieldingresistance of the spring 56. After the latch bolt has been released thespring 56 and the plug 57 will return the latch bolt to its normalposition as shown in Fig. 4. To disconnect the coupling between theparts 38 and 47 it is only necessary toapply pressure to the end of thelatch bolt 55 until it has been pressed inwardly sufliciently to clearthe female portion on the member 47 after which the parts may beseparated.

In Fig. l I have shown a composite rigid drill bit extension 7 O passingthrough horizontal joists 12 and 13. It will be extended by the additionof other sections until the bit 47 has reached the 'joist 14 or untilthis rigid extension portion spans at least three of the joists. Theserigid extension sections may be of various lengths for convenientinsertion through the apertures 71 in which the shield 25 is secured, asshown in Fig. 1.

The rigid extension portion is somewhat smaller than the ultimatediameter of the bit so that the perforations made by the bit aresomewhat larger than the rigid portion and somewhat larger than theflexible shaft which is to be subsequently employed in carrying out mymethod of operation. The bit extension sections are preferably threadedon their outside surfaces for the tail in Fig. 3, is held in drillingposition' upon a support, such as'a step-ladder or the like, in anadjustable do 72 which is adjustably secured to a clamp held in place bya screw 74 on a suitable support, such as a step-ladder 75 or the like.

The bit stock 38 may be rotated by means of an electric motor 76connected to the coupling 36 by a flexible shaft 77, when desired, or ifpreferred a hand-operated crank may be connected to the coupling 36 andthe bit stock may be manually rotated. In Fig. 5 an enlarged view of theiexible shaft is shown, and the manner of its connection to the coupling49. y

Any convenient means for controlling the operation of the electric motor76 may be employed and located near the drilling apw paratus 29, as onthe step-ladder or other suitable support, whereby the speed of themoto-r may be varied and the direction of rotation thereof may bechanged at will.

After a series of holes have been drilled through the spaced-apartobstructions in the walls, such as the joists thereof, the tool bit 47may be removed, in the manner described, through another perforation, as79, as shown in Fig. 2, and the pull-in attachment 78, may

be connected onto the end of the drillingshaft in lieu thereof. Thispull-in attachment 78 is provided with a hole into which a cord, wire,or cable, 81 is threaded and to which it is attached, so that when thedrilling apparatus is withdrawn from the perforations which it has made,the cord or wire 81 will be drawn into the said perforations so thatsubsequently a conduit cr wire may be pulled thereinto.

The use and operation of my system is as follows: A perforation is madethrough a ceiling wall 16, after which the shield 25 is placed throughthe perforation so made, to protect the bounding edges of the ceiling orthe additional portions of the wall. This shield is held in place bymeans of an inner fiange 27 and when the shield has been compressed andsubsequently expanded is secured in position to prevent its displacement. The tool 29 is now placed -through the perforation in the shield25 into the space bounded by the floor, ceiling, and joists 11 and 12,and it may be held in selected position as by the adjustable clamp 72secured to the stationary support or the stepladder 75, by the clamp 73.At this time a short bit 47 is inserted directly into the bit stock 38and the hole is first drilled through the joists 11, as at 82. Asheretofore explained the bit stock may be given a reciprocating motionby tightening the screw of the shaft 42, by turning the head 43 untilthe plug 46 makes a rather positive engagement with the rotatable nut41. As heretofore explained the bit stock 38 is directly rotated throughthe gears 34 and 37 and the feather 40 which is secured to the gearwheel 37. It will, of course, be understood that when drilling the hole82 the tool is turned around so that the end provided with one member ofthe coupling faces the joist 1l. After the hole 82 has been bored thedevice is returned to the position shown and the bit 38 is retracteduntil it is substantially Hush with the right hand side of the support.,and the projected rear portion` has entered the aperture 82. The bit isnow removed from the st0ck38 and a short section of the bit extension isinserted between the bit and the stock 38 in a manner heretoforedescribed, `without removing the tool from its position. The stock 38 isnow advanced until the bit comes into contact with the j oist 12, when ahole is bored through the joist, after which the bit and the sections ofthe extension that have been attached thereto are disconnected from thestock 38, in a manner heretofore described, and another section addeduntil the bit 47 is brought into contact with the joist 13, at whichtime other bit extensions are connected in and the stock 38 againadvanced in a manner heretofore described until a hole is made in thejoist 14. Now then the rigid bit extension is supported in three joists12, 13, and 14 in a horizontal manner. It will continue vto drill holesin substantially the samel plane as long as the rigid portion of the bitis urged forwardly and suliciently rotated. now attach the flexibleshaft 77 to the rigid bit extension 7 0 and continue the rotation of theshaft 77 and the bit by means, preferably, of an 'electric motor 76. Asthe outside portion of the rigid bit extension is screw threaded .and asit bears always upon at least threeof the supports l2, 13, and 14, thescrew threads, by their contact with the lower portion of the holes thathave been made fin the supports, operate as a means for feeding thebit-47 forwardly without the necessity of applying pressure from theoutside end of the flexible shaft. This feed is not positive so as torequire excessive power of the motor or to apply excessive strain to anyportion of the drilling mechanism, but it is sufiicient to urge forwardthe bit 47 with sufficient effect to readily drill the holes.

lVhat I claim is: l

1. The process of drilling alining holes through a series of joists orlike relatively narrow, widely spaced obstructions located in the intersace between planar surfaces of a hollow wall perforating the wallbetween joists,insert ing angled drilling mechanism through saidperforation and positioning it to work in substantial parallelism withthe planar surfaces of the wall. drilling holes by means of a bitthrough three or more forward obstructions by the addition thereto ofthreaded sections after each obstruction has been drilled through,thereby forming a rigid threaded guide as long as the span of threeobstructions, and constituting part of said angled drilling mechanism,and thereafter continuing the rotation of the bit by power or the like,which consists in applied rotatively thereto by a flexible shaft,thereby 'causing the guide by its constant thread engagement with two ormore obstructions, to advance itself and so to move the bit from aperforated obstruction across the interspace between obstructions tothat next in advance thereof.

2. Steps in the art of drilling alining -openings through a series ofjoists, in the interspace between planar surfaces of a hollow wall,which consists in drilling alining holes in three or more joists bymeans of a rigid tool having a plurality of connectable screw threadedsections forming when joined a stem long enough to span said threejoists, by applying thereto axial pressure and also rotation; andthereafter rotating said tool, substantially without axial pressurethereon, to advance said tool through engagement of its threads with theedges ofthe perforations made in the engaged joists.

3. The process of drilling alining holes through a series of joists orlike relatively narrow, widely spaced obstructions located in theinterspace between planar' surfaces of a hollow wall or the like, whichconsists in perforating the wall between joists, to form an apertureless in diameter than' the space between joists, inserting angleddrilling mechanism through said aperture, drill ing a hole into therearward obstruction bounding the inte'r-joist space, backing the drillmechanism into said hole and drilling holes through three or lnoreforward obstructions by means of a bit carried by a joined rigid guidewhich when extended has a length sulhcient to span three obstructions fand thereafter advancing said rigid guide, guiding the latter by itsengagement with the apertures in two or more of the obstructions andsuccessively drilling alining holes in more remote forward obstructions.

In testimony whereof I hereunto set my lhand in the presence of twowitnesses.

ALBERT R. LOCKE.

In the presence of SAMUEL C. GREENWALD, MARY F. ALLEN.

